The disclosure relates to the isolation of dianhydrides. In particular, the disclosure relates to the isolation of dianhydrides with low color.
Polymers such as polyetherimide are most desirably colorless or very light colored (have low color). Polyetherimide is typically produced by reacting dianhydrides with diamines. It is therefore desirable that the dianhydrides and diamines have low color in order to produce polyetherimide with low color.